Robotic garden tools, such as robotic lawnmowers are well known.
A robotic lawn mower is generally driven by an internal power source such as a rechargeable battery. The robotic garden tool may be configured to autonomously move over a ground surface that is to be treated. Battery charging is performed when the robotic garden tool is docked to a charging device, to which the robotic garden tool will automatically return when required. During a battery charging operation, electric current will be transferred from the charging device to the battery via one or several charging contacts. A charging contact may comprise a first contact member provided on the charging device and a second contact member provided on the robotic garden tool. When the robotic garden tool is properly docked to the charging device, the first and second contact members are interconnected in one or several points of connection, so as to allow transfer of electric current via the points of connection.
However, since the robotic garden tool is configured to approach the charging device autonomously, and since the ground on which the charging device is positioned may be rough and/or inclined, the robotic garden tool may sometimes arrive to the charging device in a direction which is not aligned with the docking device and/or with a lateral displacement relative to the docking device. An angular and/or lateral displacement of the robotic garden tool relative to the charging device may also occur due to other reasons, such as an unfavorable position of the robotic garden tool when initiating its movement towards the charging station.